Xu Hui, Wan Hua, Zuo Wenqi, Sun Wendell, Owens Rick T, Harper John R, Ayares David L, McQuillan David J
Research Department, LifeCell Corporation, Branchburg, NJ 08876, USA.
Tissue Eng Part A. 2009 Jul;15(7):1807-19. doi: 10.1089/ten.tea.2008.0384.
Sub-optimal clinical outcomes after implantation of animal-derived tissue matrices may be attributed to the nature of the processing of the material or to an immune response elicited in response to xenogeneic epitopes. The ability to produce a porcine-derived graft that retains the structural integrity of the extracellular matrix and minimizes potential antigenic response to galactose-alpha-(1,3)-galactose terminal disaccharide (alpha-Gal) may allow the scaffold to support regeneration of native tissue. Dermal tissue from wild-type (WT-porcine-derived acellular dermal matrix [PADM]) or Gal-deficient (Gal(-/-) PADM) pigs was processed to remove cells and DNA while preserving the structural integrity of the extracellular matrix. In addition, the WT tissue was subjected to an enzymatic treatment to minimize the presence of alpha-Gal (Gal-reduced PADM). Extracellular matrix composition and integrity was assessed by histological, immunohistochemical (IHC), and ultrastructural analysis. In vivo performance was evaluated by implantation into the abdominal wall of Old World primates in an exisional repair model. Anti-alpha-Gal activity in the serum of monkeys implanted subcutaneously was assessed by ELISA. Minimal modification to the extracellular matrix was assessed by evaluation of intact structure as demonstrated by staining patterns for type I and type VII collagens, laminin, and fibronectin similar to native porcine skin tissues. Explants from the abdominal wall showed evidence of remodeling, notably fibroblast cell repopulation and revascularization, as early as 1 month. Serum ELISA revealed an initial anti-alpha-Gal induction that decreased to baseline levels over time in the primates implanted with WT-PADM, whereas no or minimal anti-Gal activity was detected in the primates implanted with Gal(-/-) PADM or Gal-reduced PADM. The combination of a nondamaging process, successful removal of cells, and reduction of xenogeneic alpha-Gal antigens from the porcine dermal matrix are critical for producing a material with the ability to remodel and integrate into host tissue and ultimately support soft tissue regeneration.
植入动物源组织基质后临床效果欠佳可能归因于材料的加工性质，或归因于针对异种抗原表位引发的免疫反应。生产一种保留细胞外基质结构完整性并使对半乳糖-α-(1,3)-半乳糖末端二糖（α-Gal）的潜在抗原反应最小化的猪源移植物，可能会使该支架支持天然组织的再生。对野生型（WT-猪源脱细胞真皮基质 [PADM]）或缺乏半乳糖（Gal(-/-) PADM）的猪的真皮组织进行处理，以去除细胞和DNA，同时保留细胞外基质的结构完整性。此外，对WT组织进行酶处理，以尽量减少α-Gal（Gal减少的PADM）的存在。通过组织学、免疫组织化学（IHC）和超微结构分析评估细胞外基质的组成和完整性。通过在切除修复模型中植入旧世界灵长类动物的腹壁来评估体内性能。通过ELISA评估皮下植入的猴子血清中的抗α-Gal活性。通过评估完整结构来评估对细胞外基质的最小修饰，完整结构表现为I型和VII型胶原蛋白、层粘连蛋白和纤连蛋白的染色模式与天然猪皮肤组织相似。腹壁外植体最早在1个月时就显示出重塑的迹象，特别是成纤维细胞重新填充和血管再生。血清ELISA显示，植入WT-PADM的灵长类动物中，最初有抗α-Gal诱导，随着时间的推移降至基线水平，而植入Gal(-/-) PADM或Gal减少的PADM的灵长类动物中未检测到或检测到最小的抗Gal活性。对猪真皮基质进行无损处理、成功去除细胞以及减少异种α-Gal抗原，对于生产一种能够重塑并整合到宿主组织中并最终支持软组织再生的材料至关重要。
